- Allergy to donepezil or other piperidine derivatives (including fentanyl, alfentanil, sulfentanil, remifentanyl, demerol, tramadol, loperamide, diphenoxylate, betaprodine, alphaprodine, ethopropazine, anileridine, piminodine, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP),loratadine, fexofenadine